Bio-Sensing Technology Series: Microbial Fuel Cells

Welcome to the first of our Bio-Sensing Technology series, looking at Microbial Fuel Cells. This technology is led by Dr Ioannis Ieropoulos, a Senior Research Fellow in the Bristol Robotics Laboratory (BRL) and we ask him to tell us a bit more about his research.

So what is Microbial Fuel Cell technology?Microbial fuel cells employ live bacteria to produce electricity by breaking down organic matter. The technology commonly consists of two halfcells – an anode and a cathode – that are separated by an ion selective membrane. Commonly bacteria are in the anode side, and chemicals or oxygen are in the cathode side, which complete the reactions (ie close the circuit) to generate power.

What are the applications of MFC?This technology looks at utilising a wide range of organic compounds that are considered to be waste, for creating energy. The MFC technology may have potential in a domestic or village setting for the micro-generation of energy.

Applications primarily include Autonomous Robotics, stand-alone Remote Sensing, Waste and Wastewater treatment and utilisation. Further developments may include the powering of other specialized off-the-grid equipment such as portable IT systems, Environmental Monitoring tools and Medical Support apparatus.

Can you give us some examples of projects where MFC has been used?The MFCs technology has already been used to generate power for autonomous robots, such as EcoBot-I (powered by sugar), EcoBot-II (powered by flies and rotten fruit diet) and EcoBot- III (powered by wastewater).

What are you working on at the moment?The latest project, ‘Urine-tricity: electricity from urine', aims to produce electricity from urine through stacks of small-scale microbial fuel cells whilst at the same time cleaning the urine stream and getting rid of pathogens that may be found in urine. The project, if successful, has the potential to achieve energy recovery from urine and other waste streams, and produce a cleaner effluent, which is dischargeable into the environment without expensive wastewater treatment in developing world countries.